Any recs on brakes?

[Littlebeefy]

Hi guys,

I'm not loving my brakes. I'm going to make some calculated changes and I'd love some advice. Here's what I've got now: I've got a set of T-bird calipers up front and stock drums (and stock cylinders) in the back. I have a hydroboost and a Wilwood tandem MC with a Wilwood prop valve.

Currently the brakes feel weak. Also the pedal feels mushy and not a lot of grabbing power until closer to the bottom. We have bled the hell out of the system; there is no air in it. I added the hydroboost thinking it would help but it only makes it feel "mushier".

First off, I know I want to switch out my rears for some discs. I know most of the benefit of the brakes is going to come from the front, but I need the upgrade back there for towing. Plus the stock parking brake needs to be upgraded. I'm not considering the El Dorado brakes because I've heard about how difficult they can be to align properly. My buddy, who knows all things, said that the Ford Explorer discs with an integrated parking brake drum is the way to go. Moser sells a kit for the 9" that seems to be a pretty complete setup. They also sell a Wilwood package for the rear that is a 4 pot caliper with a 12.9" disc and 50% more pad surface than the Explorers. Anybody have any experience with either of these packages?

Also, what about the MC? It's a 1 1/8. Is my bore too big? Is it too small? Do I need to switch out the rears and then assess the MC? I have the MC from the F450 that I took the hydroboost out of, and I think that's a 1 5/16 bore. I also have a 1 1/4 bore from Duff that I tried before I went hydroboost but didn't love.

[85lebaront2]

Interesting issues. I have only had two vehicles with Hydroboost, both GMs with the 5.7L Diesel and their brakes were the typical GM, lock if you look at them on wet pavement.

I did a rear disc conversion on my best friend's 1995 F360 crew cab DRW pickup, his is a Powerstroke and uses a vacuum pump to operate a conventional booster and he was complaining of poor stopping power. One night we had been working at my old house getting it ready to sell and in the interest of expediency I told him just drive Darth. First corner he almost put both of us through the windshield.

The disc conversion was by a company called EGR brakes and is essentially GM stuff. It took me a bit to get it right, I have a lengthy document I put together with pictures showing the issues. His ultimate cause was a bad vacuum pump.

If I were to do a rear disc conversion, I would prefer a drum type parking brake for two reasons (a) one less potential leak point where the parking brake actuator goes through the caliper and (b) the drum style parking brake can be used even if the caliper is broken. My 1986 Chrysler LeBaron has this style rear disc brakes.

Before I went any further, I would look at the stock caliper, master cylinder and rear wheel cylinder sizes. FWIW, the larger the master cylinder, the greater the force required, smaller takes less force, but will have more travel.

[Gary Lewis]

I don't have any experience with which to answer your question. But I do have hydroboost on Big Blue, and there's nothing mushy in any possible way with it. If you press on the pedal you'd better want to slow down NOW.

I'm using the F450 master that came with the hydroboost unit and kept the rear wheel cylinders stock. But in front I'm running the '95 F350 calipers that came with the D60.

Anyway, all I'm saying is that my hydroboost system works very well. It may not be perfectly balanced, but I've not had any problems with it in any situation.

[Bronco Carl]

I used MK five (1977 or 1978) Lincoln rear disc on a 9 inch rear in my 94 F150. Worked great! I used the same rotors as the fronts, they may have to be surfaced to reduce the thickness. And different wheel studs to locate the rotors to the axle. You also get a heavy cast iron rear bearing retainer which is the caliper mounting bracket from the Lincoln. These calipers use a ramp-ball type park brake using the rear pads for the park brake. Do not use any GM rear calipers, ever, total junk.

I had excellent brake balance using the drum brake master Cylinder, booster, and proportioning valve. I checked the master Cylinder rear output port for a check valve and there was none making it acceptable for rear disc use.

[Ford F834]

I have installed a F450 Superduty hydroboost system (booster + large bore MC) on my F150. The result was very aggressive braking with almost no pedal travel. My stopping ability is definitely traction-limited.

I have considered rear disc brakes on my F350 mostly because drum systems are tedious to service. But since you mentioned towing, keep in mind that rear disc conversions often trade better performance for less friction area. It is pointless to try to compare a hypothetical system to the stock one, not knowing the pad material, heat transfer rate of the rotor, etc., but my experience towing our 28’ Streamline camper with the hydroboost F150 was that traction limited became heat fade limited quite quickly. I would be in no hurry to trade friction surface area for more aggressive performance (which the hydroboost already seems to provide in excess). My Ford 9” has the 11” drum option. I’m sure there are rear discs that outperform the drums on a 9”, even regarding brake fade, but it won’t come from a low end kit, I don’t think. After experiencing how bad rear drum brakes weren’t on the F150 I have pretty much lost any interest in discs for my F350.

Don’t know if this helps at all, just relating my experience with one solution to crumby brakes. My system needed completely gone through regardless… and I chose to replace with F450 booster and MC.

[Bronco Carl]

The rear disc's on my 2000 F350 Super Duty are not as capable as the 12 1/8 x 3 1/2 brakes I had on a 1987 E350 class C motor home. Any drum brake truck with with a heavy load on it at all times such as service bodies loaded with tools and parts or slide in campers would benefit with the use of larger diameter wheel cylinders.

[Pete Whitstone]

I don't have any experience with which to answer your question. But I do have hydroboost on Big Blue, and there's nothing mushy in any possible way with it. If you press on the pedal you'd better want to slow down NOW.

I'm using the F450 master that came with the hydroboost unit and kept the rear wheel cylinders stock. But in front I'm running the '95 F350 calipers that came with the D60.

Anyway, all I'm saying is that my hydroboost system works very well. It may not be perfectly balanced, but I've not had any problems with it in any situation.

I have to say, I feel exactly the same as Littlebeefy about my brakes. The brakes in my 2006 F150 are a different world, compared to my 81.

I too have bled the system multiple times and I'm about positive there is no air in there. I've changed just about every part of the system, including the MC (yes I properly bench bled it before install).

New calipers, new braided SS brake lines, new pads... but zero change to how the system feels. How it feels is, typical 80's overboosted, mushy, insulate you from the driving, no pedal feel brakes. They do work if you really lay into them. I'm not sure I could actually lock my front wheels, though. I realize that "impending lockup" is the state you want them in for maximum braking, and they can get there.

Maybe I've driven post-y2k trucks for so long that I forgot what they felt like in the 80's. I'd sure like to drive someone else's truck to evaluate both my brakes and my steering (which seems somewhat wayward with everything replaced except the steering gear box, which was adjusted by my mechanic).

I'd love for my brakes to have the more-instant, commanding feel that my 2006 truck has. When you talk about F450 MC's and hydroboost systems, what year parts are being used? What are the details of the conversion, anything to know besides having to run lines from the PS pump?

[Gary Lewis]

I have to say, I feel exactly the same as Littlebeefy about my brakes. The brakes in my 2006 F150 are a different world, compared to my 81.

I too have bled the system multiple times and I'm about positive there is no air in there. I've changed just about every part of the system, including the MC (yes I properly bench bled it before install).

New calipers, new braided SS brake lines, new pads... but zero change to how the system feels. How it feels is, typical 80's overboosted, mushy, insulate you from the driving, no pedal feel brakes. They do work if you really lay into them. I'm not sure I could actually lock my front wheels, though. I realize that "impending lockup" is the state you want them in for maximum braking, and they can get there.

Maybe I've driven post-y2k trucks for so long that I forgot what they felt like in the 80's. I'd sure like to drive someone else's truck to evaluate both my brakes and my steering (which seems somewhat wayward with everything replaced except the steering gear box, which was adjusted by my mechanic).

I'd love for my brakes to have the more-instant, commanding feel that my 2006 truck has. When you talk about F450 MC's and hydroboost systems, what year parts are being used? What are the details of the conversion, anything to know besides having to run lines from the PS pump?

There is nothing mushy about Big Blue's brakes. You touch the pedal the wheels will slow. You hit the pedal hard the wheels will stop. And it is easy to modulate between the two.

The F450 that Jim parted out was a '95, and that's where the hydroboost unit, master cylinder, and the Saginaw pump came from. But you don't need to change pumps as you can easily use the original C-II pump. You'll have to reroute the output from the pump to the hydroboost unit and from there to both the power steering box as well as the return. But that's not hard to do.

And speaking of the power steering box, they are not supposed to be adjusted. They are set at the factory and if they wear you can adjust it and you'll find you can take the wear and the "feel" out or you can put the wear and the feel back in. They go hand in hand.

The issue is that the cast iron of the steering box is used as the front bearing on the steering input shaft. So when it wears you have slop. You can replace the box with a Cardone or some other rebuilt unit but it won't have the front bearing replaced, so you'll have some slop. To my knowledge only Red Head and Bluetop bore out the box and put a real bearing in, and that is what is needed to take out the slop.

[Littlebeefy]

I have to say, I feel exactly the same as Littlebeefy about my brakes. The brakes in my 2006 F150 are a different world, compared to my 81.

I too have bled the system multiple times and I'm about positive there is no air in there. I've changed just about every part of the system, including the MC (yes I properly bench bled it before install).

New calipers, new braided SS brake lines, new pads... but zero change to how the system feels. How it feels is, typical 80's overboosted, mushy, insulate you from the driving, no pedal feel brakes. They do work if you really lay into them. I'm not sure I could actually lock my front wheels, though. I realize that "impending lockup" is the state you want them in for maximum braking, and they can get there.

Maybe I've driven post-y2k trucks for so long that I forgot what they felt like in the 80's. I'd sure like to drive someone else's truck to evaluate both my brakes and my steering (which seems somewhat wayward with everything replaced except the steering gear box, which was adjusted by my mechanic).

I'd love for my brakes to have the more-instant, commanding feel that my 2006 truck has. When you talk about F450 MC's and hydroboost systems, what year parts are being used? What are the details of the conversion, anything to know besides having to run lines from the PS pump?

@Pete - you described my brake feel exactly. I just want a little bit more and I run out of pedal. Also, I had the exact same steering float. That front end is not a great design in my opinion. How old are your coils and shocks? Have you tried a Borgeson steering shaft to eliminate play? Swapping to a solid axle up front has given it a tremendous improvement and I feel much more confident in the steering wheel over all. That's a whole other topic though...

My kit is not original at all. The hydroboost came from either a 97 or a 99 F450 (possibly a 95 haha). It's got the blue canister. Pretty much identical to everyone else's except for the exotic metric thread for the fittings. My pump is a heavy duty Saginaw. After I put the hydroboost in, the pedal felt softer, but no improvement in stopping power. I have 35s so I know I'm asking a lot but it seems like with the t-bird calipers up front I should be able to lock the front up if I lay full on the brakes. I'm using a Wilwood MC (both before and after hydroboost install) so that is suspect in terms of bore size.

I guess I have two separate questions:

1. the pedal feels too soft and "runs out of juice" at the end of travel. Does that mean I should increase the bore size of my MC?

2. What is going to give me better brakes for stopping distance if I'm hauling/towing: 12"+ rear discs or F350 wheel cylinders in my drums?

[Bronco Carl]

I was an automotive machinist for 30 years. Back in the 90's I discovered that the Dayton calipers used on the later 80's F250 and F350 would expand a measured .060 in. Causing a mushy pedal feel at times. Usually on the diesels with a vacuum pump that delivered a full 25 in. of vacuum giving the booster more power. We would sell the customer a 1 1/4 Dia. master cylinder from the Super Duty reducing the maximum pressure output. This solves nothing, but gives the customer a better pedal feel.

The original Dayton calipers used in the 70`s did not do this they were much heavier built!

I also resealed a lot of the Bendix hydroboost units, even the ones from GM diesel cars. They are good units and pretty trouble free.